Did You Know?: Purdue in the Arctic

March 29, 2012

Paul Shepson (left), professor of chemistry and department head, and Brian Stirm, aviation maintenance technician, will be in Barrow, Alaska, until April 2 as part of a federal project exploring the environmental effects of the Arctic's melting ice. (Photo provided)
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Four members of the Purdue community are spending a month in Barrow,
Alaska, as part of a federal project exploring the environmental effects
of the Arctic's melting ice.

Paul Shepson, professor of chemistry and department head, is a
principal investigator for NASA's Bromine, Ozone and Mercury Experiment
(BROMEX), which began March 6 and will end April 2. Also traveling from
Purdue are Brian Stirm, an aviation maintenance technician; Kerri Pratt,
a postdoctoral researcher; and Kyle Custard, a doctoral student.
Shepson and scientists from several universities across the world are
examining how the reduction in Arctic sea ice affects bromine, ozone and
mercury chemical processes.

Specifically, the scientists are trying to understand the spatial
characteristics of bromine in the atmosphere using measurements taken in
an airplane called the Purdue Airborne Laboratory for Atmospheric
Research (ALAR). The results of the research will help predict what will
happen to the atmosphere once Arctic sea ice is gone, Shepson says.

For Shepson, the work in Alaska is an extension of the more than 20
years he has spent studying the Arctic and the toll climate change has
taken on it.

"The Arctic is the canary in the coal mine for climate change,"
Shepson says. "The Arctic warms two to three times faster than the rest
of the planet, and that fact is reflected in major changes in the amount
and extent of sea ice coverage on the Arctic Ocean."

The rippling effects of warming in the Arctic are serious, Shepson
says. For example, people native to the area depend on bowhead whales
for food, but warming threatens the whales' habitat. A variety of other
Arctic wildlife depends on the existence of ice, too.

Changes in the Arctic's environment aren't just limited to that area,
Shepson says. Because Arctic ice helps regulate Indiana's weather
patterns, the state will be in for big changes if that ice depletes.

Shepson's previous work includes studying Arctic haze, a springtime
phenomenon in which ground-level ozone disappears and elemental mercury
is converted into more toxic products. Shepson's research has helped
determine that the effect involves halogens derived from sea salt.
Through his Purdue lab, Shepson also has discovered that the
photochemistry in sunlit Arctic snowpacks results in an unusual chemical
composition in the atmosphere.

Shepson says he's spent much of his career studying the Arctic
because he wants to be a positive force in the process of understanding
and communicating about the impacts of global warming.

"Climate change so far is the biggest legacy of my generation for the
planet, and I am not very happy about that," Shepson says. "To be
blunt, the Earth is precious, and we are trashing it. We can do better.
The idea that Purdue science, engineering, technology and the arts are
making that happen makes me very happy."